A number of dibenzopyran compounds recently have been found to be useful in the treatment of depression, pain and anxiety. U.S. Pat. Nos. 3,928,598, 3,944,673 and 3,953,603 describe various hexahydro-dibenzo[b,d]pyran-9-ones which have such utilities. Particular attention is drawn to dl-trans-1-hydroxy-3-(1,1-dimethylheptyl)-6,6-dimethyl-6,6a,7,8,10,10a-hex ahydro-9H-dibenzo[b,d]pyran-9-one, now generically referred to as nabilone.
Several modifications of known dibenzopyran compounds have been made in an effort to discover new compounds having enhanced pharmacological usefulness or new utilities altogether. Only a few of such modifications have included the incorporation of nitrogen in the dibenzopyran molecule. U.S. Pat. No. 3,886,184 describes certain 1-amino-3-alkyl-9-alkyl-dibenzo[b,d]pyrans. U.S. Pat. No. 3,676,462 discloses a number of 1-aminoalkyl and 3-aminoalkyl dibenzo[b,d]pyrans. Similarly, nitrogen has been incorporated into the C-ring of certain dibenzo[b,d]pyran-type compounds. U.S. Pat. No. 3,878,219 discloses dibenzo[b,d]pyrans having a nitrogen atom in the C-ring at the 9-position. U.S. Pat. No. 3,888,946 discloses similar nitrogen containing heterocycles wherein the C-ring is five membered rather than six.